BACKGROUND: Heated humidification is paramount during neonatal high-flow nasal cannula (HFNC) therapy. However, there is little knowledge about the influence of flow rate and mouth leak on oropharyngeal humidification and temperature. METHODS: The effect of the Optiflow HFNC on oropharyngeal gas conditioning was investigated at flow rates of 4, 6 and 8 L min-1 with and without mouth leak in a bench model simulating physiological oropharyngeal air conditions during spontaneous breathing. Temperature and absolute humidity (AH) were measured using a digital thermo-hygrosensor. RESULTS: Without mouth leak, oropharyngeal temperature and AH increased significantly with increasing flow (P < 0.001). Mouth leak did not affect this increase up to 6 L min-1, but at 8 L min-1, temperature and AH plateaued, and the effect of mouth leak became statistically significant (P < 0.001). CONCLUSIONS: Mouth leak during HFNC had a negative impact on oropharyngeal gas conditioning when high flows were applied. However, temperature and AH always remained clinically acceptable.
BACKGROUND: Heated humidification is paramount during neonatal high-flow nasal cannula (HFNC) therapy. However, there is little knowledge about the influence of flow rate and mouth leak on oropharyngeal humidification and temperature. METHODS: The effect of the Optiflow HFNC on oropharyngeal gas conditioning was investigated at flow rates of 4, 6 and 8 L min-1 with and without mouth leak in a bench model simulating physiological oropharyngeal air conditions during spontaneous breathing. Temperature and absolute humidity (AH) were measured using a digital thermo-hygrosensor. RESULTS: Without mouth leak, oropharyngeal temperature and AH increased significantly with increasing flow (P < 0.001). Mouth leak did not affect this increase up to 6 L min-1, but at 8 L min-1, temperature and AH plateaued, and the effect of mouth leak became statistically significant (P < 0.001). CONCLUSIONS:Mouth leak during HFNC had a negative impact on oropharyngeal gas conditioning when high flows were applied. However, temperature and AH always remained clinically acceptable.
Entities:
Keywords:
Humidity; Infant; Non-invasive ventilation; Temperature
Authors: Hendrik S Fischer; Tim L Ullrich; Christoph Bührer; Christoph Czernik; Gerd Schmalisch Journal: Med Eng Phys Date: 2016-12-30 Impact factor: 2.242
Authors: Hendrik Stefan Fischer; Charles Christoph Roehr; Hans Proquitté; Gerd Schmalisch Journal: World J Pediatr Date: 2013-10-21 Impact factor: 2.764